I was just thinking of this and never had to but what if you had to jump a piece of equipment that was 24 volt in the field and all you had was your truck and cables. 12 volt to 24 volt does not mix.
Interesting thought. Guess from my military experience, I've never had to jump off a 24 volt system when I didn't have another 24 volt vehicle around. We just hauled out the heavy cables with the huge plugs, and just plugged grill to grill with them. Suppose you could hook the 12 volt cables across just one battery, or two batteries what were plugged in parallel on a four battry system, and add the boost from the 12 volt system into half of the 24 volt ststem. Suppose you could even use two sets of cables and jump to both 12 volt sides of the 24 volt system, but that would tricky for someone who doesn't fully understand series-parallel wiring. Be interesting to see if anyone has actually had to do this. Might even be fun to stand back and watch all the loudish poppin undt spitzensparken.
:waving I have, but only a hundred times or so. You're right about going to just one battery. What I've done is to go to one battery, and hooked the cables up, positive to positive and negative to negative. I let that battery charge up a bit off the "jumping" vehicle, and then switch the cables to the second battery, and let it charge a bit. If the "dead" 24 volt system isn't too dead, that'll work pretty well. Sometimes you'll have a 24 volt system that's made up of four 6-volt batteries. In that case, you charge the first pair, and then the second pair, as if each pair was a single 12-volt battery (which, in effect, it is). I've never tried using two sets of cables and jumping both batteries at once. I've never even *wanted* to try that. You should really be familiar with that concept before you start hooking up the cables at all...
DO NOT USE 2 sets of cables to jump both batteries at once as this will short out both of the batteries in the 24 volt system. this could cause the batteries to explode unless you use 2 different source systems which have no comon connections.
Didn't know that - Thanks.
You can charge or jump a 12 or 24 with a portable dc welding machine you just need to know how to do it and have a suitable machine don't use this technique if you have a dead cell your thoughts on this?
And when placing or removing cable's ,, never ever put your face over that battery!!!!!!!!!!!!!!!!!!
With so many machines now having computers, a person needs to be careful also not to smoke the computer trying to jump start a machine.
i do it like Digger242j does it and it ok. like they said keep your face from over the battery in case it goes wrong
Using a welder to jump start is about the worst piece of advice tht can be given. Do not do it !!! It is NOT worth it. I can`t remember how many controllers I have seen burnt up. I rewired a 1200 Hitachi excavator because of it. Cost the customer $11,000 by the time it was up and running again. Worst part is they knew the batteries were bad, the super on the job told their mechanic to do it, and they fired the mechanic for it. With everything being computerized these days, the welder battery charger is not a good idea. My $.02.
If you have two different trucks/cars there you can put a pair on each one though... make sure none of the trucks or equipment is touching bumpers
I have jumped off of my miller trailblazer 302 how many times I put it in wire feed mode and set it on the right volts and then I get my mm out most of the time and check it and make sure it is the right volts and it always checks out to what the display says! I also haul equip and it happens that I get somewhere to pickup a piece of equip and it is dead I just pull my truck up there shut it off unhook 2 batt and make them 24 volt and jump it I have even pulled the batt out of semi and hauled them over by machine and did it worked great! I have never had very good luck with trying to jump a 24 volt system with a 12 volt like the other people were talkn bout but I believe if I waited long enuf it might work! My 2 bits Jerry
I've never had any luck using 12V to jump a 24V system, probably from lack of patience. I started hauling around a small El Cheapo battery from Wally World and a battery cable that's about 2' long with terminals on it. I can set it on the grill guard of my pickup and slap the cable on from the positive of the mounted battery to the negative of my mobile battery. Then I can use jumper cables to go from the negative of the mounted battery and the positive from the mobile battery to get 24V. My pickup uses the side mounted posts for its system so the top mounted posts are free to use. Even if I'm not in my pickup, I can rig up this system faster with two sets of jumper cables and a swiped/borrowed battery quicker than I can jump it going the 12V way.
That would work... after you disconnect the terminals from your truck.
I guess you're gonna have to tell me why I'd need to disconnect my terminals. I must have gotten lucky several dozen times.
Maybe I'm not thinking it out right? It would be feeding 24v into your truck is what I was thinking.
Let me rephrase the worst idea comment. If it works for you, great. If you look at the post count from a lot of the guys asking for help and it`s obvios their level of experience, I think it`s a bad idea to set them up to fail and potential damage to their machine. We have all done things that shouldn`t be done and got away with it. The next guy might not be so lucky.
I see what you were thinking, but no it's the same as hooking up a 12V jump. Even though one's a negative post and one's a positive post on their respective batteries, both of the terminals become 12V positive in a 24V system. In the 24V series systems on equipment that I'm used to, you have one ground terminal, two 12V positive terminals, and one 24V terminal which goes to the starter. There's no comparison in jumping it 24V versus 12V, saves a lot of cussing for me not to mention that low voltage will fry a starter over time. I have it on my to do list to mount another battery under my hood that is already hooked up instead of hauling it around.
If I don't have 24volt source I always hook up to pick up or whatever, as long as you hook up to 1 battery like you would another 12 volt system it's 12 volts I've done many time's but your best to do this to charge batteries one at a time and then try to start machine. That's what I always tell people when charging batteries with a welder disconnect welder before starting, and if your dealing with newer machine with a Ecm doesn't hurt to take battery cables off while charging :IMO
Works fine if you know what your doing, your dead cell comment...to add to that also do not charge a cold battery with welder it will explode. And not good idea to leave welder connected while trying to start machine.
Bravo Nelson I wish you said that
Greg you are right! But assuming they are good batteries you can unbound.them ground*) and charge them with the welder
If we have good batteries we disconect from machine, set welder at about 100 - 140 amp for a little bit to charge em up, then hook machine up and start, miller bobcats about 29 volts if i remember. We start welder with cables hooked up.
I have a little briggs&stratton motor with a handle on top of it and a belt running a 24v alternator, works like a charm and only takes a few minutes I also have a big 12/24v jump box on wheels that has 6 optima glassmat batteries in it but it cost about $1200 and weighs about 350lbs so most of the time we use the gas powered alternator that only weighs about 50# Oh and btw if you have a 12v system for example on a peterbilt and you hit it with 24v the ole girls will start in the coldest weather and have NEVER damaged an ECU or anything elecetronic by doing so, just make sure you have a few batteries in the truck to help absorb some of the higher than normal voltage. Or as others have said, I've done it off my pickup countless times, just hit one battery at a time or use 2 trucks. The other day snapon stopped by with a fancy ass $500 battery pack and it wouldn't even make the starter hit hardly. One other thing we carry on the trucks is homemade jump boxes, I use small-ish gel sell batteries (windmill power supply batteries) and put them in a PLASTIC ammo can with short cables, they work better than ANY factory made jump boxes that I've ever bought, I've seen 24v gel cell batts but have never taken time to build a 24v pack,,,,,, maybe someday Pj
Hi Powerjoke, would be interested in seeing a picture of your little homemade engine with the 24 volt alternator please? need al the help i can get up here
Now that would be a recipe for disaster. JMHO.
A friend of mine used to sell between 300 and 400 big trucks a year. The 12/24 volt jump box was strapped on the back of a golf cart. I'm guessing he jumped thousands of trucks using 24 volt without a problem. I've probably jumped 50 that way myself. It was a two person operation though. As soon as you hooked the cables someone was in the truck cranking. Snap On used to sell a 12/24 volt gas powered booster like PJ built.
Years ago a friend of mine had a factory built charging unit made out of a smallish Mac chainsaw (no bar or chain) that ran a v-belt to a one wire GM alternator. Was a sweet little light weight unit.
Interesting Yea I have heard that works great. what's the trick when to letting off of the 24 volts? I hear only do it while the starter is engaged this way it's only getting 17.5 volts. I`m looking into purchasing 5 of these magnetic oil pan heaters and welding up an aluminum box and placing them in there some way and running them off of a 3000 watt inverter wired into my service truck to heat the oil up. Any Thoughts on if this might work? http://www.oreillyauto.com/site/c/d....oap?ck=Search_N0653_-1_-1&pt=N0653&ppt=C0076
any pics of that briggs&stratton motor ??
I dont quite see your idea are you trying to heat up your bulk tank oil or?
As soon as you quit cranking unhook the cables.
We had a battery cart with two 8D's you could hook up series or parallel, had a big solenoid contactor on it with a wired remote so you could turn the key in the truck or piece of equipment then hit the remote button to bring in the jumpers. No sparks or shorts that way, and you could bring in 24V on a balky 12V unit. This was before the computers came in though, I wouldn't want to chance it with today's rigs.
Yea trying to heat up the oil to help the pistons move a little bit.
Would you stick the box against an engines oil pan? Why use a box? 5 heaters at 300 watts each = 1,500 watts. IF 1,000 watts gets into the oil then that would heat 10 gallons of oil 50 degrees F in about 10-15 minutes. That rough guestimation will be most accurate at the beginning when the oil is at the same temp as the surroundings, and much less accurate as the oil starts losing more heat as it gets hotter than the surroundings.
sounds like it might work hey? was just going to mount them in a box so i`m not fighting vs cables etc when its - 40 C need every bit of help when I get a service calls from a truckers that turn off there truck and plug it in overnight and don't bother checking if the cord is any good. real challenges here trying to get these frozen diesels started.
Ok I've played with those oil pan heaters and it is akin to peeing in the wind they are more like leave on overnight and it might keep some temp in as your engine cools down When I did those jobs here in MN we would bring out a good sized genset get the truck plugged in fix cord ect build a little shelter around the truck with cardboard and plywood shoot a torpedo heater under the truck heating the oil pan and engine bay another torpedo heater on the fuel tank 3 or four large chargers one on each battery wait an hour or two go do some other jump starts or pick up filters and some 911 so when it stalls on there #2 summer blend they put in in texas you can change filters write a bill for 600 dollars and wait for the next -40 day when the same dopy truck driver calls
I don't jump start anything off my truck as a rule, I carry a few jumper boxes and use more than one if needed. If I need more juice a buddy of mine has a gas powered jump starter that does 12 or 24 volt and propane heaters with directional heaters. Years ago I worked with an old timer who jump started with his welder all the time, the company bought his welder and he had no problems, I bought mine and figured a jumper box was cheaper than my Miller trailblazer.
Not a B&S, but there are several of these Honda powered alternators on the market here. 24v, 40amp continuous output.
Thanks for the picture queenslander. been doing some googling this morning and looks like you can get those in 200 plus amps from different manufacturers. Have a 200 amp alternator on my rig but hate putting so much of a load on it. looks like these guys make some 320 amp ones to? http://www.americanpowerinc.com/DC Gen.htm
this generator ended up being a piece of crap! do not buy!!
That's a bugger,should be a simple project .......drive an alternator with a Honda motor..... what went wrong?
When you hook it up backwards once....
Does anybody know of a commerical (make/model) 24 volt jumper box that is ac powered and could jump 2 12 volt 1000 CCA batteries on a dozer, assumming the batteries are dead.
https://www.ouelam.com/products/12-24-jump-n-carry-peak-starter-volt-amp-jump-3400
Or, if you're not writing the check......... https://www.amazon.com/NOCO-GB500-U...hvlocphy=&hvtargid=pla-4584413735847844&psc=1
WOWZERS!!!!
What am I missing. My dozer has 2 oversized batteries that weight a lot. The jump-n-carry looks like it weights about 20 lbs. If it had an ac cord, I could be convinced, but I don't see one in the description. Maybe if it is kept fully charged, it could crank my dozer for 15 seconds? But if it is cold, the dozer may take longer than that to start.
Your not missing anything a jump box wont work worth a darn on that dozer I used them daily in for years in the tow truck they dont last very long the batterys get weak Handy if your using it a lot and can afford to replace as needed but even then if it was cold you would need a couple to get a dead battery off and running on big trucks that were froze they were not of much use If your looking for a ac powered jump you need a boost charger they will take a little time to charge you can use one 24v one or 2 12 volt ones or one 12v and switch batterys after they charge Personally I find keeping good batterys to be well worth it Followed by a long set of very heavy jumper cables and the knowledge to use them
Nothing better than good batteries,except good cables going to the starter.My truckcrane has double runs of 4/0 from the batteries to the starter,it 2 8D batteries running the 12 v starter. Just touch the button and the 6-71 lights up.
I've always done the "charge 1 battery with jump vehicle alternator" followed by "charge other battery" and then hit if after I give a bit of charging. I have had battery carts to use, last one was the derrick outfit at the yard. I think it was a 4 battery cart
I believe my jump stater unit is a made by goodall, will do both 12 and 24 volt, engine driven, pretty simple concept and really handy to have on the service truck. The issue with using small batteries to crank anything 24 volt just enough to get them started is frying the starter solenoid and then having to take the starter off and get fixed or replaced completely, low voltage kills more 24 volt starters than anything and as of yet in this thread I've never seen that mentioned so I though I would. As for frying electrical components via jump starting with excess voltage, things must have been hooked up wrong, a lot alternators when charging correctly for 24 volts will put out up 28-29 volts on the machine itself, especially if the batteries are very low or nearly dead. I'm not sure even computerized machines know if the alternator within the machine itself is charging the batteries or if your using a jump starter unit or even a welder to do the jumping with as long as you hook things up correctly. Done it thousands of times with many computerized machines and never yet taken a computer out or fried anything. But I have destroyed many starters over the years with low voltage and trying to crank it and get a machine going, maybe not on the spot, but over time trying to crank it when it barely rolls over..................will eventually get the starter. So after many thousands spent on starters related to low voltage, I did invest in a used jump starter unit, I think it paid for itself the first month from saved downtime alone. We have also swapped batteries on most machines, to top thread semi batteries, that way, no matter where we are at, or what machine we have, we can if need be, switch batteries out on a dead machine with even those off the service truck or spares we keep on the service truck, then figure out which battery is bad, [usually a dead cell in one battery] and charge the other good battery and put it back in the machine along with a new good battery or a new battery, whichever we have on hand in the field. This whole concept of every machine having their own specific battery size and dimension and needing that specific battery was enough to put me over the edge with so much wasted time.
Speaking of jump starting with welders , any opinions on that? My 75ton Lima is 24 v we just put a new double fan heater in it not thinking of the draw on the system after a few starts and stops throughout the day next day dead batteries in the middle of the shift twice . I jumped with the welder,400 amp lincoln diesel with manual throttle/idle. I turn all settings as low as they go and leave it running at idle. Hooked to 24 v it takes 5 mins to bring the batteries back up.
All this talk of jumpstarting and such reminded me of what we had at the shop. Not sure if it was accurate but it was always referred to as "The Airplane Starter". This was basically a huge battery charger, think of a 3 foot cube on wheels that on anything other than a flat smooth surface took two men and a boy to move more than few feet. It plugged in to a 440 outlet and as I recall put out 32 volts. Hook that up to a dead 24 volt machine in freezing temps and it would crank over like the middle of the summer after a short lunch break! I have a feeling it would not be good to connect it to any of these computer controlled machines as I bet it probably did not put out pure DC voltage. It also had at least 200 feet of cord on the input side which might have been one of the reasons if you touched the handle while power was on you would feel a little tingling! Not 100% sure but think it ran off 3 phase and only had a three conductor cord. A few years before I retired company had MSHA inspectors who said it was not to be used unless we converted to 4 conductor grounded cable and that included rewiring all the outlets it was used on, so it got put back in the corner of shop with a "DO NOT USE" tag on it!
I have a jump starter I bought from Napa and it works wonders. I have been using these things for years and I've never found anything better. I've jumped multiple big machines in a day with no problems using them. I had one go bad some years ago when the 12/24 switch shorted through. Another employee was using it when it blew up. I took the pieces back to Napa and showed them why it blew and they gave me a new one. No problems at all ever since. I bought four of them for the various branches at the Cat dealer and they did away with those leased jumper monstrosities. We tossed the big battery cart with the two 8D batteries. I use this box all the time on appraisal work for machines that couldn't be caressed by charging one battery at a time off the pickup.
caressed, oh tender mercies
Yeah, used to use the old man's Lincoln 400 amp stick welder to start machines, lowest range all the way down, hook up the cables and turn the crank until the headlight/work lights got nice and bright. Wait five minutes and roll her over.. shop lights might dim a bit now and then, but if there was anything left of the starter motor, they'd turn. NOT recommended with anything having transistorized components, this was back before even electronic ignition was a thing.
The problem with using a stick welder is the initial voltage spike (open circuit volts) could be over 90 volts and you don't know what the voltage is when hooked directly for jump starting. It's similar to gouging where it's been suggested the voltage could be 35-40 volts.
We never connected the leads unless the key was already in the start position. As soon as the leads touched the battery terminals, the starter was spinning or sparks were flying. Never had a failure that could be attributed to jumping that way. That was on old machines though. Scarcella had a fleet of 631 and 641B machines in a big storage yard southeast of Mosses Lake. They wanted to trade some of the relics and I had to go look at them. The people there weren't real happy when I told them I had to see them running and be able to move all the functions. They started every one of them with their welding truck. It was a smokey valley by the time I left there.
Napa has the Jump-N-Carry JNC1224, which looks like a much bigger version of the Jump-N-Carry that was listed earlier. Amazon has it for around $350 which is $100+ less than Napa. It weighs 40 lbs. I'm guessing this is the one JohnC has (or something comparable).
Remember back in the 90’s when there was an abundance of caution regarding ECM’s? We were going to destroy them with our welders and improper jump starting. Disconnecting Cat J1/J2’s every time we struck an arc. More ECMs got damaged with bent pins and messed up connections than electrocuted by welding. The OEM’s have very specific instructions for welding prep. I don’t see folks taking any precautionary precautions today except for common sense ground placement. Have any one of you fellas ever destroyed a ECM?
I’ve welded on dozens of machines and never had an issue.
I always pull the ground or switch off the disconnect before welding. I know many welders that just strike an arc with it all connected and never saw a failure. Honestly, I've seen only 2 legit failed ECMs. One was due to water intrusion. The other one simply failed. No outside factors like boosting or welding.
I fried an alternator one time, working long way from the alternator, but it was an AC welder. Anybody else use the little inverter welders for a battery charger? just turn the amps down to whatever you feel like and hook it up, make sure the polarity is correct first.
Can’t say that I’ve ever witnessed an ECM damaged from welding or jump starting, either. I think ECM’s are most fragile during the programing process when something happens to stop the process, like battery voltage dropping below limits or a door on a light vehicle being opened ( turning on a BCM). Then, you end up with a brick that you can’t do anything with.
Ive seen those rigs ,i think Hobart made some of them and they looked like a welder. Id be interested to know what the open circuit voltage is on an Sam400 Lincoln running at at idle? Hooked to 24 v for a coupe of minutes and everything turns over fine. However i had more starting problems today so it will interesting to see if the alternator is working or not after a few welder starts.
Are the sam machines a CV machine ? A volt meter would answer that question. Bob
A sam400 is a CV/CC switchable machine.
Good point.Yes they have both cc and cv . We had been stick welding so it was set on CC
You can use your welder to charge 24 volts just don't hook up to the batteries . A short charge would help start easier and not be as rough on the starter. Bob
Didn't happen at our shop, one of our trailers was having landing gear supports replaced at a shop this was about 10 years ago. Carrier unit--fried the ECM. So I always disconnect the ground from battery before welding--always have only takes a few seconds. The shop tried to say the welding didn't cause it-well the unit was just shut off about 2 hrs before with no issues.
Cat guidelines are to shut off master switch or if none then disconnect battery cable. We weld on thumbs, catwalks every day plus use welding to fix brackets and get broken bolts out never had a problem. If I had to dig out every ECM and unhook it it would take a half day to do that to weld one broken bolt out.
Always disconnect battery, I don't know why anyone wouldn't take the few seconds to do so. My dad had a flatdeck put on his truck years ago, go to pick it up won't start fuel pump done, shopped admitted they didn't disconnect batteries. It's was from welding, or the 1 in a billion chance it managed to die at the exact same time. I bet after paying for the tow bill and shop bill fixing it they disconnected batteries from now on.
Depends on the welder, the one we used had a special low amp setting, we hooked the jumpers up to the battery being careful to observe polarity, then with the dial cranked as low as it would go, fired the welder up, it was single phase 220. As long as you have a battery in circuit it will pull the voltage down, we had to crank her up ten or fifteen turns, as stated until the headlights got good and bright. I'll bet if you check most older battery chargers they have fairly high open circuit voltages, they just built the transformers to put out so many amps with a battery load voltage of 13.5 or whatever, no real regulation. As far as electronics yeah, always remove battery grounds and always connect your welder ground as close as physically possible to the weld. Gotta love guys that ground to the frame and then weld on something where the current has to pass through a bearing or two....
I hadn't read much of this thread since Tuesday and just thought about making the comment on how some guys get lazy and on say a front end loader hook the ground lead to the cutting edge and weld where ever else they need to work! Can't say I ever saw a problem related to welding but then I think most of the guys at the shop were pretty smart about keeping the circuit as short as possible!
I always disconnect batteries on customer equipment, don't need a well it worked before.... You should also be mindful of ground placement as far as bearings/bushings too, we've fixed a few things that other people have nuked the bearings on cause they grounded on the other side of a bearing.
As far as jumping a 24v piece if I'm out in BFE I'll hit one batt at a time with cables from the truck. Usually through I just put a 24 v start/charger in the rig and drive over to the dead machine and run the charger off my engine drive. If it's a reoccurring no start call without an obvious sign, like hey dumb ass you left all the work lights on again, I'm quickly going to start checking batteries and cleaning connections too.